Work out center attire

I don't get this...
We get to the work out center right when it opens, at 7AM.
Now when I go to the workout center first thing in the morning like that I just get out of bed and put on whatever I'm going to work out in.  That way, I can just get there and begin working out.
I still followed this routine when I had to go straight to work from working out - I just brought my bag with necessities and cloths, put them in the locker room, then began working out.

Several of the people at our French workout center seem to get up, get fully dressed as if they're going to work, come to the workout center carrying their gym bag with workout cloths, change in the locker room, then work out. At 7AM.

I don't get it - why would you get fully dressed at 6:30AM just to come to the workout center and change.  One lady even goes all the way with the hose, heels, skirt suit and full makeup. Then changes to work out.

I just don't get it.